1. Field of the Invention
The invention relates to a method for generatively producing at least one area of a component and to an apparatus for carrying out such a method.
2. Discussion of Background Information
A method and an apparatus for generatively producing a component are disclosed, for example, in German patent DE 196 49 865 C1. The component is made up of individual powder layers which are each fixed to the preceding powder layer by means of a laser beam guided in accordance with a cross-sectional geometry of a component model. In the case of alloys which are not suitable for fusion welding, such as Mar M247, however, the high local temperature gradient between the molten bath and adjoining component areas can lead to hot cracking.
DE 10 2007 059 865 A1 proposes, for example for setting stress profiles, post-treating the powder layer by means of the introduction of heat after the melting or after the solidification of the melt. Material characteristics such as hardness, toughness or strength and also the material behavior can thereby be locally influenced in a targeted manner.
Patent application WO 2008/071165 A1, in the name of the applicant, proposes reducing the hot cracking by global heating of the component in the area of the powder layer to be produced. This effect can only be achieved, however, in the case of a relatively low feed rate.
It is also known for the component to be preheated by means of induction in the powder bed. This has the disadvantage that it may lead to an inhomogeneous temperature distribution in the case of complex component geometries, even despite adaptation of the induction coil geometry. This has negative effects on the component quality.
It is an object of the invention to provide a method for generatively producing at least one area of a component which eliminates the aforementioned disadvantages and prevents or at least greatly reduces hot cracking particularly in the case of a high feed rate, and also an apparatus for carrying out such a method.
This object is achieved by the method and by the apparatus according to the present invention as set forth below.